lots of pump and ceremony as china's president welcomed vice president joe biden. the president called biden an old friend and praised u.s.-china relations. biden described the relationship between the two countries as full of promise. their public remarks gave no hint of the tension, however, between the united states and china concerning air space over the east china sea. however, senior officials traveling with the vice president say during private talks, biden told the president that the u.s. does not recognize china's newly declared air defense zone over that disputed area and that the u.s. has deep concerns about the situation that this is about as delicate as a regional situation can get. yesterday, biden assured japanese leaders that he would push china over the issue. >> we will, the united states, are deeply concerned by the attempt to unilaterally change the status quo in the east china sea. this action has raised regional tensions and increased the risk of accidents and miscalculation. >> and that is the big fear, of course. this dispute could put tys w